Rio de Janeiro: Brazil's deeply unpopular President Michel Temer insisted today that a truck strike crippling the country will end within hours, even as drivers paralysed fuel, goods and food deliveries.

Temer said he had "absolute conviction that between today and tomorrow" the crisis, which stretched into its eighth day, would finally end.

In a tweet, Temer gave a slightly longer horizon of "one to two days." Despite Temer's confidence, significant numbers of truck drivers stood firm and some appeared to be radicalised, calling for the government to step down.

Late Sunday, Temer caved in to their main demand for lower diesel costs, but Monday saw renewed disruption across Latin America's biggest economy, which is already suffering from the aftermath of a deep recession and political instability ahead of October general elections.

More than 550 road blockages by truckers were mounted across 24 of the country's 27 states, the federal highway police said.

Shortages of aviation fuel shuttered eight airports. Traffic to the huge Santos seaport near Sao Paulo, which usually receives 10,000 trucks a day, shrank to a trickle.

Although there has been some improvement since the army was ordered to intervene on Friday, with armed soldiers escorting fuel trucks on priority routes, enormous lines of cars were still forming at gas stations.

Many supermarkets around the country struggled to source fresh food. Producers reported having to slaughter stocks of chickens because they had no access to the feed, while others threw out thousands of litres of spoiled milk.

Hospitals in Rio de Janeiro and Sao Paulo had to cancel non-urgent surgeries and at least 13 states reported scrapping university classes.
Adding to the disruption in Rio, the key BRT commuter system operated at only 22 per cent capacity, while in Sao Paulo the bus system ran at 70 per cent capacity.

The truckers are angry over the rise in diesel costs from 3.36 reais (92 US cents) a litre in January to 3.6 reais before the strike. On May 26, it hit 3.8 reais per litre. After urgent negotiations with representatives of the truckers, Temer agreed to cut the diesel price by 0.46 reais a litre for 60 days.

That concession hammered the value in state-controlled oil major Petrobras, one of Brazil's most dominant companies, which is due to face a strike by its own workers on Wednesday. Shares dropped 14 per cent on Monday and another 14 per cent last Thursday, while the Ibovespa index in Sao Paulo closed 4.5 per cent lower.